Australia have postponed their Test tour to Bangladesh this month because of security concerns.

The two-Test series was due to begin in Chittagong on Friday, 9 October.

Cricket Australia (CA) said "an independent security assessment found a risk of terrorism in Bangladesh targeting Australian nationals".

Bangladesh police are investigating the murder of an Italian aid worker who was shot in Dhaka on Monday. The Islamic State group has said it is responsible.

The Bangladesh Cricket Board (BCB) said it was disappointed by CA's decision but was committed to rescheduling the series at a later date.

The BCB added it did not agree with the view that Bangladesh was unsafe, describing the country as "one of the safest environments for holding international sporting events".

CA had initially delayed the team's scheduled departure on 28 September while it worked on a "revised security plan".

But it now says official advice meant it had no alternative but to postpone the tour.

"We have worked tirelessly to find a way for the tour to proceed, but in the end it was simply not possible," CA chief executive James Sutherland said.

"We had hoped that the security concerns would fade, but unfortunately the advice we have received from government, our own security experts and independent security advisors has clearly indicated that there are now high risks to our people should they make the trip.

"From an Australian perspective, the safety of our players and officials is our highest priority. We will work with the Bangladesh Cricket Board to reschedule the tour as soon as possible."

On Wednesday, the BCB Board had promised "VVIP" treatment for the Australian team, saying they would be given the same level of security afforded to visiting heads of state.

England are due to tour Bangladesh to play two Tests and three one-day internationals in October and November 2016.